Contact indicating valve actuator for gas-operated circuit breakers

ABSTRACT

The movable contact of a gas blast operated circuit interrupter has a piston connected thereto, which is connected to either an exhaust chamber or to a high-pressure gas supply. The three-way control valve, controlling the opening and closing operations of the piston-actuated movable contact, is linked to a bellcrankshaped valve operating lever which is moved by an insulating operating rod extending down to ground potential. An indicator lever is pivotally connected to said operating lever and has a stationary pivotal support. The arrangement causes the insulating operating rod, extending down to ground potential, to indicate the opening and closed circuit positions of the separable contact structure and, additionally, effects valve operating movement.

United States Patent FOREIGN PATENTS 664,544 6/1965 Belgium ABSTRACT: The movable contact of a gas blast operated circuit interrupter has a piston connected thereto, which is connected to either an exhaust chamber or to a high-pressure gas supply. The three-way control valve, controlling the opening and closing operations of the piston-actuated movable contact, is linked to a bellcrank-shaped valve operating lever which is moved by an insulating operating rod extending down to ground potential. An indicator lever is pivotally connected to said operating lever and has a stationary pivotal support. The arrangement causes the insulating operating rod, extending down to ground potential, to indicate the open and closed circuit positions of the separable contact structure and, additionally, effects valve operating movement.

CLOSED POSITION (NO SIGNAL) CROSS-REFERENCES TO RELATED APPLICATIONS Applicant is not aware of any related applications pertinent to the present invention.

' BACKGROUND OF THE INVENTION In U.S. Pat. No. 3,290,469, issued Dec. 6, 1966 to Winthrop M. Leeds, and assigned to the assignee of the instant application, there is illustrated and described a gas blast operated circuit interrupter having a piston actuated movable contact. The rear side of the contact operating piston is either connected to an exhaust connection or to a high-pressure source of gas, such as compressed air, by a three-way control valve. Such circuit breaker structure is also disclosed in U.S. Pat. application Ser. No. 625,212 filed Mar. 22, 1967, by Winthrop M. Leeds and Harvey E. Spindle, and likewise assigned to the assignee of the instant application. However, in the lattermentioned application, the three-way control valve is at line potential; and an insulating rod, extending between line and ground potential, mechanically actuates the three-way control valve. It would be desirable, of course, to have a positive indication of the contact position, to enable operating personnel to know, definitely, whether the contact structure of the circuit breaker is open or in the closed circuit position. This is, of course, obvious when maintenance work is performed on the circuit breaker structure, since the contacts should be open before series disconnecting contacts are opened.

It is, accordingly, desirable to have a simple and positive means for not only operating the three-way control valve, but also indicating, with reliability and complete assurance, the open and closed circuit positions of the contact structure.

Generally, the prior art has divided these different functions into two separate instrumentalities. One instrumentality has caused the actuation of the control valve to operate the contact piston, and the other instrumentality, acting independently, has provided an indication of contact open and closed positions. It would, of course, be desirable to combine such instrumentalities in a simple and reliablemanner into a single means, relatively inexpensive, to effect actuation of the control valve, and also as a part thereof, indicate the contact open and closed positions with complete assurance.

SUMMARY OF THE INVENTION According to the present invention, there is provided a gas blast operated circuit breaker with the movable contact thereof connected to a contact actuating piston, the rear side of which may either be connected to an exhaust or, alternatively, to a high-pressure supply of gas. These pneumatic connections are readily affected by a three-way control valve, which is mechanically linked to a bellcrank lever having one arm thereof pivotally connected to an insulating operating rod extending, perhaps a considerable distance, down to ground potential. A pivotally mounted indicator lever is mechanically connected to the movable contact and is actuated thereby. The pivotally mounted indicating lever has a fixed pivot, and, additionally, pivotally supports the aforesaid bellcrank valve operating lever. By such an arrangement, a simplified and highly reliable means is provided for not only effecting operation of the three-way control valve, but also a positive indication of contact position is assured. As a result, only a single operating rod need extend the considerable distance down to ground potential. Additionally, the operating rod, with the mechanical movements described, may cause an auxiliary switch operation, the latter being connected into the control circuitry, as desired.

A general object of the present-invention is to provide an improved control valve actuator, which simultaneously indicates the contact open and closed circuit positions.

A further object of the present invention is to provide a simple and reliable valve operating means and .contact indicator involving only the use of a single insulating operating rod extending a considerable distance down to ground potential, the arrangement being particularly desirable for high-voltage circuit breakers say, for example, controlling circuits of 500 KV OR 700 KV, for example.

Further objects and advantages will readily become apparent upon reading the following specification taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view taken through a gas blast operated circuit breaker illustratingan embodiment of the invention, the contact structure being illustrated in the closed circuit position;

FIG. 2 is a fragmentary view of the valve operating linkage, and a portion of the insulating operating rod, the contact structure being in the closed position, but a trip open signal having been applied by downward pulling on the insulating operating rod;

FIG. 3 is a view similar to that of FIG. 2, but illustrating the breaker in the open position with no opening or closing signal being applied; and

FIG. 4 is a similar view of the operating linkage with the breaker being in the breaker open position and a closing signal being applied by pushing the insulating operating rod upwardly slightly.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral 1 generally indicates a gas blast operated circuit breaker shown in the closed circuit position. As shown, the circuit breaker 1 generally comprises a separable contact structure 2 including a relatively stationary contact 3 and a movable contact 4, which is piston actuated. A compression spring 5 and gas pressure within the breaker acts to effect breaker opening operation, and breaker closing operation is provided by the entrance of high-pressure gas, such as compressed air, into the space 6 rear-wardly of the moving contact actuating piston 7. Also, the space 6 on the rear side of the contact piston 7 may be exhausted to permit the compression spring 5 and the gas pressure within the interior of the breaker casing 8 to effect contact opening movement.

A three-way control valve 10 is provided to either effect exhausting of the space 6, or the pressurizing thereof depending upon the position of the control valve 10. As shown in FIG. 1, the control valve 10 is in the position wherein high-pressure gas, from a storage tank 11 at the lower portion of the breaker 1, effects entrance of high-pressure gas to the region 6 on the rear side of the contact operating piston 7 to effect the closing thereof in opposition to the compression spring 5.

To effect a breaker opening operation, as mentioned, the three-way control valve 10 is moved to the right, as viewed in FIG. 1. This exhausts the region 6 on the rear side of the piston 7, and simultaneously closes off the conduit 13 leading to the high-pressure storage tank 11.

For certain applications, it is desirable to have a highly effective arc extinguishing gas, such as sulfur-hexafluoxide (SP gas 14, as the arc extinguishing gas, whereas the operating gas 15 for effecting closing movement of the contact 7 piston 7, may be ordinary compressed air, which is stored in the high-pressure storage tank 11. Communication between these two gases 14, 15 is prevented by a rolling sleeve diaphragm 16, which is secured not only to the contact piston 7, but, as shown in FIG. 1, to the periphery 17 of the operating 4 cylinder 18, within which the operating piston 7 reciprocally lever 24 is connected to a floating link 26, which is connected to the three-way control valve stem 27 to effect the opening and closing operation thereof. The other arm 24b of the bell crank 24 is pivotally connected to a relatively long insulating operating rod 28, which extends downwardly, say for a considerable distance, in high-voltage applications, and is connected to an actuator pl ton 29. As shown in FIG. 1, the actuator piston 29 reciprocally moves within an operating cylinder 30, and its movement is controlled by a three way control valve 31, which is solenoid operated, for example, by a pair of opening and closing solenoids 32, 33.

The energization of the closing and opening solenoids 32, 33 is effected by respective push buttons 34, 35, and the circuit therethrough is disconnected by an auxiliary switch 36, which constitutes an extension of the insulating operating rod, as shown.

FIG. 1 illustrates the breaker in the closed circuit position. To efl'ect an opening operation of the circuit breaker, a trip open signal, such as closing the push button 35, energizes the solenoid 32 to efiect the rotation of the rotary three-way control valve 31 to admit high-pressure to the top side of the actuator piston 29. This drives the actuator piston 29, and hence the insulating operating rod 28 downwardly, say, for example, one-half inch. When the breaker 1 opens, the indicator lever 21 will return to the position shown in FIG. 3, and push the insulating rod 28 down an additional one-half inch.

F IG. 3 illustrates the position of the various linkage parts in the breaker open position with no opening or closing signal being applied.

FIG. 4 illustrates the breaker l in the open position with a closing signal applied by energizing the closing push button 34. This will move the insulating operating rod 28 upwardly one-half inch. In the breaker closed position, the indicating lever 21 will cause an additional upward travel of the insulating operating rod 28.

From the foregoing, it will be apparent that the insulating operating rod 28 not only effects operation of the three-way control valve at high potential, but, additionally, by the incorporation of the indicator lever 21, the insulating operating rod 28 indicates the contact open and closed positions. in other words, by the use of a single and unitary operating rod 28, two functions are performed by the same instrumentality. The simplicity and positive operation of such a device, together with the low cost, is a desirable feature in high-voltage circuit breakers, where the distances from ground potential up to the high-voltage level may be of the order of 25 to 30 feet in height.

Additionally, it will be noted that the auxiliary switch operation 36 may be effected by the movement of the insulating operating rod 28 to control certain control circuitry in opening and energizing circuits in the breaker open and closed circuit positions.

Although there has been illustrated and described a specific structure, it is to be clearly understood that the same was merely for the purpose of illustration, and that changes and modifications may readily be made therein by those skilled in the art, without departing from the spirit and scope of the invention.

I claim:

1. A compressed gas operated circuit breaker including, in combination:

1 a casing including a pair of separable contacts;

2. one of said separable contacts being a piston actuated contact;

3. three-way control valve means for effecting the exhausting or pressurizing of one side of the contact piston;

4. indicating lever means mechanically connected to the movable contact of the circuit breaker;

5. said indicating lever means pivotally supporting valve actuating means; and

6. an insulating operating rod extending to ground potential and effecting operation of the valve actuating means. 2. The compressed gas operated circuit breaker of claim I,

wherein the indicating lever means is a bellcrank-shaped lever, and is pivotally mounted upon a stationary support.

3. The compressed gas operated circuit breaker of claim 2; wherein the valve actuating means is a bellcrank-shaped operating lever pivotally connected to one arm of the firstmentioned bellcrank-shaped indicator lever.

4. A compressed gas circuit breaker including, in combination:

1. means at least partially of insulating material defining an enclosed circuit breaker casing;

2. an arc extinguishing gas having a higher dielectric strength than air disposed within said casing;

3. a pair of separable contacts disposed within said casing,

one of which is piston actuated;

4. three-way control valve means for effecting the pressurizing or exhausting on one side of the contact piston;

5. pivotally mounted indicating lever means mechanically connected to the movable contact;

6. valve actuating means for effecting operation of said three-way control valve pivotally supported on said indicating lever means; and

7. an insulating operating rod connected to said valve actuating means and extending down to ground potential.

5. The combination according to claim 4, wherein the indicating lever means is a bellcrank-shaped lever pivotally supported, and the valve actuating means is a bellcrank-shaped lever pivotally connected to one arm of the first-mentioned bellcrank-shaped lever. 

1. A compressed gas operated circuit breaker including, in combination:
 1. a casing including a pair of separable contacts;
 2. one of said separable contacts being a piston actuated contact;
 3. three-way control valve means for effecting the exhausting or pressurizing of one side of the contact piston;
 4. indicating lever means mechanically connected to the movable contact of the circuit breaker;
 5. said indicating lever means pivotally supporting valve actuating means; and
 6. an insulating operating rod extending to ground potential and effecting operation of the valve actuating means.
 2. one of said separable contacts being a piston actuated contact;
 2. an arc extinguishing gas having a higher dielectric strength than air disposed within said casing;
 2. The compressed gas operated circuit breaker of claim 1, wherein the indicating lever means is a bellcrank-shaped lever, and is pivotally mounted upon a stationary support.
 3. The compressed gas operated circuit breaker of claim 2, wherein the valve actuating means is a bellcrank-shaped operating lever pivotally connected to one arm of the first-mentioned bellcrank-shaped indicator lever.
 3. a pair of separable contacts disposed within said casing, one of which is piston actuated;
 3. three-way control valve means for effecting the exhausting or pressurizing of one side of the contact piston;
 4. indicating lever means mechanically connected to the movable contact of the circuit breaker;
 4. three-way control valve means for effecting the pressurizing or exhausting on one side of the contact piston;
 4. A compressed gas circuit breaker including, in combination:
 5. The combination according to claim 4, wherein the indicating lever means is a bellcrank-shaped lever pivotally supported, and the valve actuating means is a bellcrank-shaped lever pivotally connected to one arm of the first-mentioned bellcrank-shaped lever.
 5. pivotally mounted indicating lever means mechanically connected to the movable contact;
 5. said indicating lever means pivotally supporting valve actuating means; and
 6. an insulating operating rod extending to ground potential and effecting operation of the valve actuating means.
 6. valve actuating means for effecting operation of said three-way control valve pivotally supported on said indicating lever means; and
 7. an insulating operating rod connected to said valve actuating means and extending down to ground potential. 